Prepositions are words which begin prepositional phrases.
A prepositional phrase is a group of words containing a preposition, a noun or pronoun object of the preposition, and any modifiers of the object.
It is a word such as after, in, to, on, and with. Prepositions are usually used in front of nouns or pronouns and they show the relationship between the noun or pronoun and other words in a sentence. They describe, for example:
- the position of something:
Her bag was under the chair.
The dog crawled between us and lay down at our feet.
His flat was over the shop.
- the time when something happens:
They arrived on Sunday.
The class starts at 9 a.m.
Shortly after their marriage they moved to Colorado.
- the way in which something is done:
We went by train.
They stared at each other without speaking.
Some prepositions are made up of more than one word, for example:
They moved here because of the baby.
We sat next to each other.
The hotel is perched on top of a cliff.
It is useful to locate prepositional phrases in sentences since any noun or pronoun within the prepositional phrase must be the preposition’s object and, therefore, cannot be misidentified as a verb’s direct object.